1. Field of the Invention
This invention relates to a glass multilayer wiring board for mounting large-scale integrated circuit chips and a method for manufacturing the same. More particularly, it relates to a multilayer wiring board with insulating layers of a glass having a low dielectric constant and a method for manufacturing the same.
2. Description of the Prior Art
The conventional ceramic multilayer wiring board for mounting large-scale integrated circuit (LSI) chips has been manufactured by printing wiring patterns with a tungsten conductor paste on green sheets (unsintered base sheets) made of alumina as a major constituent, filling the through-holes with said conductor paste, laminating the resulting green sheets, and sintering the laminated green sheets at 1500.degree. C. under a non-oxidizing atmosphere. However, in an alumina-base multilayer wiring board thus prepared, since the relative dielectric constant of alumina is about 9 and the resistivity of tungsten wiring conductor is about 1 .OMEGA./cm, the delay time of signal propagating through the multilayer wiring system is too large to cope with the operation speed-up.
For the above reason, there is a demand for a multilayer wiring board in which an insulating material having a low relative dielectric constant and a metallic wiring conductor of low resistance are combined. To answer the demand, there have been proposed (a) a method employing glass as the material for the insulating layer, on which is provided wiring conductors by using as the material a low-resistance metal such as gold, silver, or copper [Japanese Patent Kokai (Laid-open) No. 127,112/76] and (b) a method employing a crystallized glass containing .alpha.-cordierite or .beta.-spodumene as a major constituent for the material of insulating layer, [Japanese Patent Kokai (Laid-open) Nos. 111,517/79 and 128,856/80]. However, the relative dielectric constant of these insulating glass layers is 5 or above and, hence, is still required to be lower in order to permit the operation to be carried out at a higher speed.